Japanese Patent Application Laid-Open No. 2015-009733 (Patent Literature 1) describes a vehicle seat which can store a seat back and a seat cushion connected to the seat back on a storage floor made in a lower position than a vehicle body floor and includes: a support base provided on the vehicle body floor, located under the seat cushion, and connected to the lower end of the seat back in a rotatable manner; a support leg with an upper end fitted to the seat cushion and a lower end connected to the support base; a leg holding member fitted to the support base to hold the lower end of the support leg in an attachable/detachable manner; and a lock device which is fitted in the vehicle seat and can lock the support leg held by the leg holding member (see the claims).